TIA-835-B defines pre-paid data service in terms of pre-paid client (PPC) and pre-paid paid server (PPS) functionality. The client functionality is responsible for metering the data usage. The server functionality is based on authorizing pre-paid usage and provides quotas and thresholds for pre-paid functionality. In the scope of TIA-835-B, the PPC functionality for simple IP is implemented within the packet data service node (PDSN) element of a code division multiple access (CDMA) network.
There are several inherent problems with this implementation. For a roaming pre-paid paid subscriber to be able to access simple Internet Protocol (IP) service, the visited network must be a CDMA network, and in addition, the PDSN through which the pre-paid subscriber will access the internet must be capable of and enabled to support pre-paid functionality. If the PDSN does not have PPC functionality, then a pre-paid subscriber will not be able to access simple IP. A visited network may not be willing to allow roamers to utilize pre-paid functionality for various reasons, including the additional processing overhead incurred for such transactions.
Therefore, it is the purpose of this invention to enable pre-paid subscribers to have access to simple IP whether or not the visited network in which they are roaming supports pre-paid simple IP access.
In the context of this invention, there are some relevant terms that will be defined here. A packet data session describes continuous use of packet data service by the user. A packet data session begins when the user invokes a packet data service. A packet data session ends when the user or the network terminates the packet data service. For simple IP service, changing points of attachments constitutes a change in the packet data session because a new IP address is assigned by the new point of attachment. A point of attachment refers to the node where the Mobile Station (MS) is connected to access the IP network. For this invention, examples of points of attachment are PDSNs, GGSNs, WI-FI nodes, and WiMAX nodes. Mobile Station refers to equipment, such as a mobile phone, that is used by a user to access a wireless network. A pre-paid packet data service is a function that allows a user to pay in advance for the use of packet data service. A pre-paid server (PPS) is a function that manages pre-paid accounts for the users. It maintains the pre-paid accounts on a per user basis or on a per service type basis for a user. It communicates with the pre-paid client for control of the pre-paid packet data service. A pre-paid client (PPC) is a function that resides in the wireless IP network and communicates with the pre-paid server function (PPS) to control the prepaid user's packet data session. It requests pre-paid account authorization for a user and monitors the user's packet data session to determine when the limits of the authorization are reached.